Multiple expansion joint



y 2, 1967 R. H. INGRAHAM ETAL.

MULTIPLE EXPANSION JOINT 2 Sheets-Sheet 1 Filed Sept. 28, 1964 wim Filed Sept. 28, 1964 May 2, 1967 R. H. INGRAHAM ETAL. 3,317,223

MULTIPLE EXPANSION JOINT 2 Sheets-Sheet 2 United States Patent C) 3,317,223 MULTIPLE EXPANSION JOINT Ronald H. Ingraham and Lloyd D. Grames, Wellsville, N.Y., assiguors, by mesne assignments, to The Air Preheater Company, Inc., a corporation of Delaware Filed Sept. 28, 1964, Ser. N 0. 399,468 '2 Claims. (Cl. 285-299) This invention relates to flexible expansion joints for use in apparatus between independent parts thereof that move relative to one another when subjected to variations in thermal conditions. More particularly this invention relates to heat exchange apparatus wherein a housing memher, a bank of heat exchange elements therein, and the necessary connecting ductwork are all held in fluid-tight relationship while they are permitted to move relative to one another when subjected to thermal variations that effect expansion and contraction of the several members.

Expansion joints of the well known bellows type are commonly used where required to accommodate differences in the expansion of the several parts of heat exchange apparatus, expansion joints of this type being used separately and individually wherever required. An arrangement of this type requires that there be a multiplicity of sizes and shapes of the joints and plurality of places where used such that they occupy excessive space, are expensive to install, and difllcult to maintain.

Accordingly it is the principal object of this invention to provide a multiple type expansion joint for use between three or more relatively movable members. It is a further object of this invention to provide a housing for heat exchange apparatus utilizing therein one or more multiple expansion joints that eflectively preclude leakage of fluid while permitting variations in thermal expansion. Moreover it is still another object of this invention to provide the above-mentioned fluid-tight multiple expansion joint for use in a space usually required for a single expansion joint.

These and other objects of my invention will become more apparent when read in conjunction with the drawing in which:

FIGURE 1 shOWs a side elevation of a tube type heat exchanger that employs expansion joints of the type described in the foregoing disclosure.

FIGURE 2 is an enlarged detail drawing of the arrangement that comprises the invention, and

FIGURE 3 shows a modified form of the invention, and

FIGURE 4 is a schematic drawing showing a conventional expansion joint arrangement for apparatus having a plurality of elements movable with respect to one another.

Apparatus of the type defined herein comprises a heat exchanger having a core of tubular units 22 supported at its ends by tube sheets 24 whereby the tubular units may be interposed in a housing structure 25 having spaced inlet and outlet ducts 26 and 28 that direct a first fluid through the tubular units 22. Other inlet and outlet ducts 32 and 34 in the housing direct a sec-nd fluid over the tubes in order that heat from one fluid may be readily transmitted through the tube walls to the other fluid.

Inasmuch as the temperature of the several fluids traversing the flow passageways of the heat exchanger may vary greatly, the apparatus enclosing the several fluids may be subjected to considerable expansion and contraction during normal operation. A conventional arrangement frequently utilized to preclude leakage while permitting relative movement between adjacent parts of such apparatus is to simply provide a flexible joint 36 between the relatively moving housing 25 and core 27 in the manner shown in FIGURE 4 of the drawing.

Inasmuch as additional relative movement obtains be tween core 27 and duct 26 another expansion joint 38 is positioned between the heat exchange core and the connecting duct work to permit the heat exchanger and the housing to expand and contract independent of one another. This arrangement extends longitudinally to occupy excessive space and to require the installation of an independent expansion joint for each pair of relatively movable members.

In accordance with the present invention we provide a compact joint arrangement for use between a multiplicity of relatively movable parts such as a tube core, a surrounding housing, and an axially aligned duct means. Our expansion joint arrangement is adapted to permit complete freedom from interference between parts while it eflectively precludes fluid flow between the several parts.

An expansion joint according to the invention shown in FIGURE 2 comprises an essentially thin, flexible, metallic member 42 formed with a substantially U-shaped cross section and having one edge secured at 44 in fluid tight relation to the housing member 25 while the space edge thereof is connected to the core member 27. The core member 27 slidably abuts the housing member 25 while the flexible joint 42 precludes fluid flow therebetween. Inasmuch as relative axial movement similarly occurs between the housing 25 and axially spaced duct 26, a flexible fluid-tight joint 48 is additionally required to preclude fluid flow therebetween. The flexible joint 48 is thus arranged concentrically around flexible joint 42 to occupy a minimum of space. The flexible joints 42 and 48 may be press formed from a plurality of parts and joined as by welding along abutting flanges 50 to provide an economical method of manufacture.

A second form of the invention illustrated in FIGURE 3 comprises an annular U-shaped flexible member 52 having one end secured at 54 in fluid-tight relation to the housing 25 while its remote end is secured at 56 to the most remote movable member, here illustrated by duct member 26. An essentially annular, plane flexible member 58 lying within the U-shaped member 52 has a flanged edge 62 connected thereto and its other edge 64 connected to the core member 27 or another intermediate movable member.

By this arrangement movement of the housing 25, core member 27 or duct 26 is readily accommodated by flexure of the expansion means connected thereto. Moreover, as any individual portion 52 or 58 of the expansion joint is moved directly by virtue of its being connected to a movable portion of the heat exchanger, it is also moved indirectly when another portion of the expansion joint is forced to conform to movement of that portion of the heat exchanger assembly connected thereto.

Thus any portion of the flexible joint assembly 52, 58 is subject to flexure even though it is not connected directly to that portion of the supporting structure which is being moved as a result of thermal expansion or contraction to thereby distribute such flexure over the entire joint assembly.

It is apparent that apparatus of this type may be further modified to permit relative expansion and contraction between more than three independent members, and that other changes may be made in the basic arrangement shown without departing from the spirit of the invention. It is accordingly intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. An expansion joint comprising three interfitting coaxial ducts forming a passageway, said ducts being movable relative to each other, a seal arrangement for said ducts comprising a first flexible member disposed thereabout, said member being generally U-shaped in transverse section with one leg of the U secured to and about one of the ducts and with the other leg secured to and about another of the ducts and with a portion of the third duct exposed to the interior of the U, a second flexible member disposed about and secured to said third duct at a location intermediate the depending legs of the first flexible member and being constructed and arranged to form a seal with said one duct.

2. The seal arrangement of claim 1 wherein said second flexible member is of U-shaped transverse section and is embraced within said first flexible member, said second member having one leg of the U secured to said third duct and the other leg secured to said one duct.

References Cited by the Examiner UNITED STATES PATENTS MEYER PERLIN, Primary Examiner. ROBERT A. OLEARY, Examiner.

A. W. DAVIS, Assistant Examiner. 

1. AN EXPANSION JOINT COMPRISING THREE INTERFITTING COAXIAL DUCTS FORMING A PASSAGEWAY, SAID DUCTS BEING MOVABLE RELATIVE TO EACH OTHER, A SEAL ARRANGEMENT FOR SAID DUCTS COMPRISING A FIRST FLEXIBLE MEMBER DISPOSED THEREABOUT, SAID MEMBER BEING GENERALLY U-SHAPED IN TRANSVERSE SECTION WITH ONE LEG OF THE U SECURED TO AND ABOUT ONE OF THE DUCTS AND WITH THE OTHER LEG SECURED TO AND ABOUT ANOTHER OF THE DUCTS AND WITH A PORTION OF THE THIRD DUCT EXPOSED TO THE INTERIOR OF THE U, A SECOND FLEXIBLE MEMBER 